Not surprising that Biogen is conducting this study. Their market share of MS patients using Tysabri is far short of what they expected at this point in time. And with the risk of PML climbing each month, they have to do something to prop up sales.
Considering that the efficacy of the CRAB drugs is not very good, it won't take much in this trial to show that Tysabri gives better results. And guess who is going to pay for this trial in the long run?